Arduino Com port has disappeared

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    User avatar
    Tempest8008
    Posts: 25
    Joined: Tue Sep 12, 2017 3:42 pm

    Thu Jan 11, 2018 6:34 pm

    It was working fine earlier today.
    I was playing around with some serial communications Sketches and all of a sudden the com port (com11 on this LP) disappeared and won't come back.

    Some background:

    I'm working on making this board do several things. I have a daughter board that is connected via USB that has an LTE Modem device as well as a GPIO (GPS) device on it. The modem is using Com ports 4, 6, and 7. The GPS is running off of port 5.

    Com1 is the only other port available.

    Any suggestions on troubleshooting steps I can use to reconnect to the on-board Arduino? I want to use the pinouts for status LEDs, so was playing around with different blink Sketches. I want to write to those pins from a C# application, and was figuring simple serial comms where I fire single digits to the Arduino where the Sketch would translate them into commands would be the way to go. In retrospect there are probably better ways, but I'll get it figured out. :P

    If my Arduino board on his LattePanda will ever talk to me again.

    Thanks (in advance).

    User avatar
    Tempest8008
    Posts: 25
    Joined: Tue Sep 12, 2017 3:42 pm

    Thu Jan 11, 2018 7:04 pm

    FYI with the daughterboard disconnected the system only shows COM1.

    User avatar
    Tempest8008
    Posts: 25
    Joined: Tue Sep 12, 2017 3:42 pm

    Thu Jan 11, 2018 7:15 pm

    Google is my friend.
    Found this online. The last section, starting with "The trick to fixing this...." worked for me.
    I can see the board again.

    TL/DR: Must have uploaded a Sketch with the wrong board selected and it garbled the Arduino boot sequence and prevented it from being detected at the USB level.
    Re: Micro disappears from device manager after few seconds
    #3
    Mar 14, 2013, 09:14 am Last Edit: Mar 14, 2013, 11:16 am by hiduino Reason: 1
    What happens initially is when you reset the Micro it’s bootloader USB driver is running and Windows enumerates the USB port as COMxx. But then after a timeout period the bootloader exits and runs the sketch code. As part of the sketch code there is a USB driver code running and Window enumerates the USB port as a different COMyy.

    What happens too often and usually not on purpose is that someone did not properly select "Arduino Micro" under the Tools->Boards menu when they were trying to upload a new sketch to the Micro. So the wrong core code in the sketch got uploaded to the Micro, without the proper USB driver code as part of the sketch.

    So what is happening when you reset the Micro the bootloader USB driver is running and shows up in Windows for a short time until it times out and then proceeds to execute the wrong sketch code without the proper USB core code. This will then show up in Windows as Unknown device.

    The trick to fixing this is first restart (important step) your Arduino IDE software and make sure you select “Arduino Micro” under Tools->Boards. Make sure you select a basic sketch like Blink. The board may disappear from the Serial Port list but don’t worry. Then try to upload the sketch. During the build process (right after the compile process) you need to hit the reset button on the Micro again that should get the bootloader running just in time for the upload to proceed and hopefully restore the proper sketch code with the correct USB driver in it. You may need to retry this several times until you get the timing right.

    User avatar
    ED209
    Posts: 222
    Joined: Tue Apr 19, 2016 3:31 pm

    Fri Jan 12, 2018 2:43 pm

    Interesting. Thanks for sharing this trick!

    User avatar
    ED209
    Posts: 222
    Joined: Tue Apr 19, 2016 3:31 pm

    Fri Jan 12, 2018 2:43 pm

    BTW, what kind of arduino project you are working on?

    User avatar
    LattePanda
    Site Admin
    Posts: 2657
    Joined: Wed Jan 20, 2016 9:09 am

    Mon Jan 15, 2018 10:13 am

    Yeah, would you mind to tell more about your project?
    Looking forward to it. :D
    Enjoy Tinkering with LattePanda ! :lol:

    User avatar
    Tempest8008
    Posts: 25
    Joined: Tue Sep 12, 2017 3:42 pm

    Tue Jan 16, 2018 3:38 pm

    I work for a company that makes software for airports. We have a product that to date has been running on Panasonic Toughpads, running in Windows, or on dedicated vehicle computers running Win7 embedded. We want to make a "lite" version of the same setup.

    Our software receives GPS coordinates and compares that to a GIS enabled map. That then provides visual and audio cues to the driver advising of proximity to runway safety areas where no ground traffic is supposed to go without clearance from the control tower. This setup also reports the GPS coordinates to a web site via a cellular data connection, where an operator can view in real-time the location of ground vehicles in or around the airport (that are set up with the device). The existing setup also lets the vehicle see OTHER vehicles on the airfield, and allows them to coordinate their work.

    The Lite version we want to make uses the LattePanda as the Windows OS, coupled with the Arduino to control visual cues via LEDs.

    The daughter-board we have created has GPS and cellular modem modules attached, and connects to the USB headers and pinouts for the Arduino and our LED bank. The whole thing is going to go in a custom enclosure we have created that is about 20cm long, 10cm high, and 12cm wide. It is all powered by a 12v power adapter that contains our UPS circuit that is designed to keep the LP up and running for about 60 seconds, giving the OS enough time to shut down when external power is lost.

    We have been experiencing challenges, but we're getting there.

    User avatar
    LattePanda
    Site Admin
    Posts: 2657
    Joined: Wed Jan 20, 2016 9:09 am

    Fri Jan 19, 2018 6:41 am

    Awesome! Many thanks for your sharing . How's everything going! :P
    Enjoy Tinkering with LattePanda ! :lol:

    User avatar
    Tempest8008
    Posts: 25
    Joined: Tue Sep 12, 2017 3:42 pm

    Fri Feb 02, 2018 4:57 pm

    We have noticed we are still occasionally losing the Arduino Leonardo com port.
    We rectify this by hitting the reset button on the LattePanda, but eventually when the unit is put in the case we'll lose access to this, and we can't expect our customers to be hitting that button to fix a problem.

    Is there any way to reset the Arduino board via software and Com 1?

    User avatar
    LattePanda
    Site Admin
    Posts: 2657
    Joined: Wed Jan 20, 2016 9:09 am

    Tue Feb 06, 2018 7:08 am

    Hi, we can just reset the Arduino part via the Reset button, and the Com1 is for another Uart device.
    Sorry for your inconvenience.
    And what kinds of case are you using , the one you can not press the button. :?:
    Enjoy Tinkering with LattePanda ! :lol:

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